Manually openable leakproof package construction

ABSTRACT

A manually openable leakproof package construction comprising perforations across one portion of the construction with the perforations leaving a sufficiently weakened portion such that the package may be manually torn open across the perforations, a manually frangible layer of leakproof material such as plastic overlying said perforations, and with the leakproof layer acting to seal off the perforated portion such that the package is leakproof prior to the time the package is manually torn open.

United States Patent Wink et al.

[54] MANUALLY OPENABLE LEAKPROOF PACKAGE CONSTRUCTION [72] Inventors: Anton Wink, Detroit; Robert J. Williams, Birmingham, both of Mich.

[73] Assignee: Cadillac Products Inc.

[22] Filed: May 27, 1971 [21] Appl. No; 147,402

[52] US. Cl ..229/66, 229/51 AS, 222/541,

206/56 AA [51] Int. Cl. ..B65d 33/00 [58] Field of Search....229/66, 58, 22, 51 RT, 51 CE, 229/17 G, 14 BL; 206/56 AA, 57 A, 57 AB;

[56] References Cited UNITED STATES PATENTS 1,959,364 5/1934 Hothersall ..222/541 2,789,728 4/1957 Britton ..222/541 X Aug. 29, 1972 2,992,118 7/1961 Daline ..229/75 3,175,752 3/1965 Stabbnow ..229/66 X 3,349,993 10/1967 Ells et al. ..229/66 3,379,360 5/1968 Crossley ..229/22 3,472,369 10/1969 Schuster ..229/66 X Primary ExaminerDavis T. Moorhead Attorney-Harness, Dickey & Pierce [57] ABSTRACT A manually opcnable leakproof package construction comprising perforations across one portion of the construction with the perforations leaving a sufficiently weakened portion such that the package may be manually torn open across the perforations, a manually frangible layer of leakproof material such as plastic overlying said perforations, and with the leakproof layer acting to seal off the perforated portion such that the package is leakproof prior to the time the package is manually torn open.

11 Claims, 9 Drawing Figures Patented Aug. 29, 1972 3,687,358

.2 Sheets-Sheet 1 v INVENTORS $272 144';

BACKGROUND OF THE INVENTION This invention broadly relates to a manually openable leakproof package means. More particularly this invention relates to a manually openable leakproof plastic bag, for example of single or double wall construction.

It has been conventional in the past to form leakproof packages such as for example leakproof plastic bags for packaging various commodities. One technique for preparing such leakproof plastic bags for use in packaging various items is to extrude a thin walled cylindrical tube of the plastic material. The cylindrical tube of plastic material is then folded over, with or without a gusset, and transversely cut and heat sealed at spaced points to form a plurality of bags which are open at the top.

Subsequently these bags are filled with various items and then the top open portion sealed off, for example by heat sealing the plastic together across the open top, thus resulting in a leakproof plastic bag holding the containerized contents. One difficulty with actual usage of such a leakproof plastic bag resides in the fact that users thereof have significant difficulty in manually opening the bag, especially in any kind of a uniform fashion. For example, the plastic bags are difficult to manually open because the plastic material used in their construction is necessarily relatively strong and thus the bags are difficult to manually tear open. On the other hand if the plastic material from which the bags are constructed is made weak enough such that they can be easily torn open then the bags are subject to leakage through puncturing, tearing, etc. which might occur during the normal handling thereof prior to the time it is actually desired to manually open the bag. Furthermore, if these plastic bags are manually torn open through rather strained physical exertion, then still the opening which results from the tear is usually non-uniform in size and directional orientation, making it difficult to remove or pour the contents from the bag in an orderly fashion.

Accordingly, it is a primary object of this invention to provide an improved manually openable leakproof plastic bag construction. A related object resides in the provision of such a bag capable of being manufactured in a continuous manner utilizing conventional bag making processes.

Another object of the present invention is to provide an improved manually openable leakproof package means.

Another object of the present invention is to provide a manually openable leakproof plastic bag of single or double wall construction.

Another object of the present invention is to provide a manually openable leakproof package means which includes a manually frangible layer of leakproof material overlying a weakened portion in the package which weakened portion is formed of perforations positioned in the package at a predetermined orientation, with the frangible layer and the perforations being readily capable of being torn to open the package in an easily facilitated and desirable manner.

Another object of the present invention is to provide an improved manually openable leakproof plastic package wherein a plastic material forms the main construction of the package and the plastic material is formed of a relatively non-frangible material and, wherein at least one section of the plastic is perforated with the perforations being covered over by a layer of leakproof material which is relatively frangible.

Other objects, features and advantages of the present invention will become apparent from the subsequent description and the appended claims taken in conjunction with the accompanying drawings, wherein like numerals designate like elements.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a package means or bag of double walled plastic construction in accordance with the invention;

FIG. 2 illustrates a cross sectional view taken along the line 22 of FIG. 1 showing the bag slightly expanded;

FIG. 3 illustrates a view of the package in accordance with this invention taken from the circled area designated 3 in FIG. 2 to show the construction of the tear open portion of a double walled bag;

FIG. 4 shows how a similar tear open portion would be constructed in a single walled bag;

FIG. 5 illustrates a view of another embodiment of a plastic bag in accordance with the invention which bag includes a tear open pouring spout on one side thereof;

FIG. 6 illustrates another embodiment of the invention wherein the plastic bag includes a tear strip for opening the tear portion;

FIG. 7 illustrates a cross sectional view taken along the line 77 of FIG. 6;

FIG. 8 illustrates another embodiment of the invention wherein the plastic bag includes a tear off portion which extends across the entire top of the bag; and,

FIG. 9 illustrates a cross sectional view taken along the lines 9-9 shown in FIGS. 5 and 8.

SUMMARY OF THE INVENTION Briefly stated, the present invention is comprised of a manually openable leakproof package means comprising means defining a materially weakened portion in said package means, said weakened portion being sufficiently weakened such that said package means may be manually torn open at said weakened portion, a manually frangible layer of leakproof material overlying said weakened portion, and means sealing said frangible layer to said package, said sealing being continuous and fully surrounding said weakened portion.

DESCRIPTION OF PREFERRED EMBODIMENTS There follows a description of the preferred embodiments of the invention but it is not intended that the invention should be limited hereby, as other variations and embodiments will become apparent from the invention disclosed.

FIGS. 1-3 illustrate a plastic bag designated 10 of double walled construction as indicated by walls 12 and 14 (FIG. 2). A gusseted portion designated 16 may if desired be formed at the bottom of the bag 10 by proper folding of the plastic material from which the bag is made, and subsequent sealing of the gusset edge areas designated 18.

A manually openable portion of the plastic bag is shown within the area designated of FIG. I. The construction of the manually openable portion 20 is more clearly understood from the cross sectional views shown in FIGS. 2-3. The two plastic walls 12 and 14 are perforated across one side of the bag as indicated by the perforations 22 and 24. Just above and below the perforations the two walls 12 and 14 are joined together for example by heat sealing at the positions designated 32 and 34. The perforations 22 and 24 in and of themselves would cause leakage in the plastic bag 10, however, the perforations 22 and 24 are covered over by a manually frangible layer 40 of leakproof material which is heat sealed to the bag 10 at positions 41 and 43. The result is that the perforations cause a weakened portion in the plastic bag 10 and the perforations themselves are covered by the manually frangible layer 40 which is sealed to the plastic bag 10 to stop any leakage through the perforations. Yet the bag itself can be readily opened manually by breaking or tearing apart any desired length of the perforations which give way essentially simultaneously with the frangible layer 40. This permits a user of the inventive package disclosed herein to easily open the package by tearing same along the predetermined and properly orientated tear open portion 20. Moreover, when the package is manually opened it can be opened to either a small or large extent, as may be determined by the length of the tear which the user of the package desires to make.

FIG. 4 shows a cross section of a tear open portion 20 as would be constructed in a single walled bag, as opposed to the double walled construction of the FIG. 3 cross section.

The thickness of the plastic material used to form the package is not critical other than that the plastic material should be such that it can be torn across the perforations which are placed therein to an adequate extent. Any number of different thermoplastic materials may be used as the plastic for forming the package described herein. Furthermore, it has been found that essentially any number of different thicknesses may be used for the plastic material which forms the walls 12 and/or 14. Also the package may be of single walled construction as shown in FIG. 4 or the package may be of doubled walled (as shown in FIG. 2) or higher construction.

In accordance with our inventive concept the frangible strip or layer 40 must be strong enough to properly seal off the package over the perforations such that the package is leakproof, however, the frangible layer must be weak enough to easily tear when a person using the package desires to manually open same. Generally speaking a plastic material, for example polyethylene, having a thickness of approximately 1/4 mil is sufficient to seal off the perforations, and such a thickness for the frangible layer 40 has been found to tear easily when it is desired to manually open the package. Preferably the perforations should be on the outside of the package construction, but they may also be positioned on the inside with the frangible layer being on the outside of the wall construction. Furthermore, the package construction disclosed herein could be of other material than plastic, for example it could be of cardboard construction.

FIG. 5 illustrates another embodiment of the plastic bag in accordance with this invention wherein a pour spout designated is formed at the left side of the bag as shown in FIG. 5. The pour spout 50 extends partially around both sides of the bag 10. The construction of the pour spout is shown in more detail by the cross sectional view of FIG. 9 taken along line 9-9 of FIG. 5. The wrap around tear open spout is comprised of the manually frangible layer of plastic material 40 which overlies and seals off the perforations 24. When it is desired to open the pouring spout, the bag is merely gripped in the hands and the tearing action is initiated at the point designated 51 in FIG. 5 and the tearing action is continued until the pouring spout is opened by tearing of the perforations 24 and frangible layer 40, such that the pouring spout is opened back to the point 52 shown in FIG. 5.

In the FIG. 6 embodiment of the invention a tear strip designated and shown in more detail in the cross sectional view of FIG. 7, is capable of-being grasped at the tab portion 61 and then pulled outwardly and to the left as shown in FIG. 6 to open the bag 10. The tear open strip 60 is formed at perforations 63 which outlines the tear open strip as shown in FIG. 6. The tab portion 61 of the strip 60 is cut away cleanly from the wall 14 of the bag so that it can be folded out and grasped by the fingers to open the bag by pulling the tear strip 60. The inside face of the tear strip 60 is covered by the frangible layer 40 of plastic material which is heat sealed at points 41 and 43 to the wall 14 of the bag. The frangible layer 40 as shown in FIG. 7 is also heat sealed to the tear strip as shown at 70, such that when the tear strip is grasped and pulled off the manually frangible layer 40 will also be torn open.

FIG. 8 shows the embodiment of the invention wherein the entire top of the bag 10 may be removed through the provision of a tear off portion designated 20a which extends across the entire top of the bag. The detailed construction of the tear open portion of 20a which extends across the top of the bag 10 is shown in the cross sectional view of FIG. 9 which is taken along line 9-9 in FIG. 8. Generally in order to open the tear off top shown in FIG. 8 it is only necessary to initiate a tearing action across the bag by gripping it with the hands, for example, and tearing from the point 81 across to the point 82, or vice versa.

It should also be appreciated that the bag embodiments shown in FIGS. 5-9 may alternatively be of double walled (or higher) construction rather than the single walled construction shown in these figures.

While it will be apparent that the preferred embodiments of the invention disclosed are well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

l. A manually openable leakproof package means comprising:

means defining a materially weakened portion in said package means,

said weakened portion being sufficiently weakened that said package means may be manually torn open at said weakened portion,

a manually frangible layer of Ieakproof material overlying said weakened portion, and

means sealing said frangible layer to said package, said sealing being continuous and fully surrounding said weakened portion.

2. The package means of claim 1 wherein,

it is of double wall construction.

3. The package means of claim 1 wherein,

said frangible layer is on the outside of the package means.

4. The package means of claim 2 wherein,

said frangible layer is on the inside of the package means.

5. A manually openable leakproof plastic bag, of single or double wall construction, comprising:

6. The bag of claim 5 wherein,

it is of double wall construction 7. The bag of claim 5 wherein,

said overlying leakproof means are on the outside of the plastic bag.

8. The bag of claim 6 wherein,

said overlying leakproof means are on the inside of the plastic bag.

9. The package means of claim 1 wherein a tear open spout means is formed on at least one side of the package means by a wrap around tearable weakened portion and corresponding wrap around manually frangible layer which overlies said weakened portion.

10. The package means of claim 1 wherein a tear open means is included in at least one side wall of the package means and wherein said tear open means includes a manually grippable tear open strip which can be pulled to open the package means.

1 l. The package means of claim 1 wherein a tear off portion extends across the entire top of the package means and which tear off portion is capable of being manually torn off to open the entire top of the package means. 

1. A manually openable leakproof package means comprising: means defining a materially weakened portion in said package means, said weakened portion being sufficiently weakened that said package means may be manually torn open at said weakened portion, a manually frangible layer of leakproof material overlying said weakened portion, and means sealing said frangible layer to said package, said sealing being continuous and fully surrounding said weakened portion.
 2. The package means of claim 1 wherein, it is of double wall construction.
 3. The package means of claim 1 wherein, said frangible layer is on the outside of the package means.
 4. The package means of claim 2 wherein, said frangible layer is on the inside of the package means.
 5. A manually openable leakproof plastic bag, of single or double wall construction, comprising: a plastic material means forming the main construction of the bag and said plastic material being of relatively nonfrangible material, perforation means in at least one portion of the bag construction, leakproof means overlying said perforation means and being sealed to said bag to prevent any leakage therethrough, said overlying leakproof means being relatively frangible such that it may be subjected to tearing along with essentially simultaneous tearing of the perforation means to open the bag.
 6. The bag of claim 5 wherein, it is of double wall construction.
 7. The bag of claim 5 wherein, said overlying leakproof means are on the outside of the plastic bag.
 8. The bag of claim 6 wherein, said overlying leakproof means are on the inside of the plastic bag.
 9. The package means of claim 1 wherein a tear open spout means is formed on at least one side of the package means by a wrap around tearable weakened portion and corresponding wrap around manually frangible layer which overlies said weakened portion.
 10. The package means of claim 1 wherein a tear open means is included in at least one side wall of the package means and wherein said tear open means includes a manually grippable tear open strip which can be pulled to open the package means.
 11. The package means of claim 1 wherein a tear off portIon extends across the entire top of the package means and which tear off portion is capable of being manually torn off to open the entire top of the package means. 